(S)-(-)-2-Chloropropionitrile has been prepared from (S)-(+)-alanine,and the ORD curves have been obtained in several solvents and in the gas phase.A reaction field extrapolation of the solution data to the gas phase led to an estimated value of [alpha]_D = -21°,whereas the interpolated gas phase value is -8°.The specific rotation was found to be temperature dependent in ethylcyclohexane solution over the range 0-100 deg C.Although rotation of the methyl group leads to large calculated effects on the specific rotation,it does not lead to the temperature dependence.Rather,a low frequency mode at 224 cm~(-1) was found to be responsible.This is a mixed mode involving methyl torsion and C-C ident toN bending.The specific rotations calculated at the B3LYP/aug-cc-pVDZ level including electric field dependent functions are in very good agreement with the measured gas phase values.
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